/* Single-page reading layer. All chapters remain in normal document flow. */
html {
  scroll-behavior: auto;
  scroll-padding-top: 102px;
}
.reading-chapter {
  display: block;
  min-width: 0;
  scroll-margin-top: 24px;
}
.reading-chapter:focus {
  outline: none;
}
.reading-chapter + .reading-chapter {
  border-top: 2px solid #a9bec9;
  margin-top: 64px;
  padding-top: 42px;
}
.reading-intro {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  flex-wrap: wrap;
  font-size: 11px;
  color: var(--muted);
  margin: 0 0 24px;
}
.reading-mode {
  padding: 0 9px 15px;
  border-bottom: 1px solid var(--line);
}
.reading-mode strong {
  display: block;
  font-size: 17px;
  margin-top: 8px;
}
.reading-mode p {
  font-size: 11px;
  color: var(--muted);
  margin: 5px 0 12px;
}
.reading-mode .eyebrow {
  font-size: 9px;
  letter-spacing: 0.12em;
}
.reading-mode label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font-size: 10px;
  color: var(--muted);
}
.reading-mode progress {
  width: 100%;
  height: 5px;
  display: block;
  margin-top: 7px;
  border: none;
  background: #e2ebef;
  accent-color: var(--cyan);
}
progress::-webkit-progress-bar {
  background: #e2ebef;
}
progress::-webkit-progress-value {
  background: var(--cyan);
}
.sidebar a {
  min-height: 35px;
}
.sidebar a[aria-current="location"] {
  color: #005e72;
  background: #e4f0f3;
  font-weight: 700;
}
.sidebar a[aria-current="location"] .nav-num {
  color: #005e72;
  font-weight: 700;
}
.chapter-header {
  display: grid;
  grid-template-columns: 94px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  margin-bottom: 32px;
}
.chapter-number {
  font: 14px var(--mono);
  letter-spacing: 0.1em;
  color: var(--cyan);
  padding-top: 7px;
}
.chapter-header h2 {
  font-size: clamp(1.7rem, 2.8vw, 2.7rem);
  line-height: 1.5;
  margin: 8px 0 15px;
}
.chapter-header .lede {
  color: #486170;
  font-size: 16px;
  max-width: 820px;
}
.chapter-header .eyebrow {
  margin-top: 0;
}
.summary-panel h3 {
  margin: 0 0 16px;
  font-size: 1.1rem;
}
.section-heading h3 {
  font-size: 1.3rem;
  margin: 0;
}
.source-block h4 {
  font-size: 1.13rem;
  margin: 1.6em 0 0.65em;
}
.expanded-detail {
  border: 1px solid var(--line);
  background: #fff;
  padding: 18px 22px;
  margin: 18px 0;
  min-width: 0;
}
.expanded-detail > h4 {
  margin-top: 0;
  font-size: 13px;
}
.figure-card .expanded-detail {
  border: none;
  background: #f6f8f9;
  padding: 12px;
  margin-bottom: 0;
}
.ocr-text {
  font-size: 12px;
  line-height: 1.8;
}
.reading-progress-line {
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: #284352;
}
.reading-progress-line span {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--bright);
  transform: scaleX(0);
  transform-origin: left;
}
.reading-finish {
  background: #e8f0f3;
  border: 1px solid #c6d7df;
  margin-top: 56px;
  padding: 34px;
}
.reading-finish p {
  font-size: 14px;
  color: var(--muted);
}
.reading-finish h2 {
  font-size: 24px;
  margin-top: 12px;
}
.back-top {
  position: fixed;
  right: 24px;
  bottom: max(18px, env(safe-area-inset-bottom));
  z-index: 20;
  padding: 10px 14px;
  border: 1px solid #afc5d1;
  border-radius: 6px;
  background: #fff;
  color: #24586b;
  text-decoration: none;
  font-size: 12px;
  min-height: 44px;
  box-shadow: 0 3px 15px #0c223218;
}
.reading-chapter .persistent-demo {
  top: 78px;
}
.site-footer {
  padding-bottom: 65px;
}
@media (max-width: 850px) {
  html {
    scroll-padding-top: 92px;
  }
  .sidebar {
    overscroll-behavior: contain;
  }
  .reading-chapter .persistent-demo {
    top: 70px;
  }
  .chapter-header {
    grid-template-columns: 70px minmax(0, 1fr);
    gap: 16px;
  }
  .back-top {
    right: 16px;
  }
  .sidebar a {
    min-height: 44px;
  }
}
@media (max-width: 600px) {
  .reading-chapter + .reading-chapter {
    margin-top: 46px;
    padding-top: 30px;
  }
  .chapter-header {
    display: block;
  }
  .chapter-number {
    margin-bottom: 15px;
  }
  .chapter-header h2 {
    font-size: 26px;
  }
  .chapter-header .lede {
    font-size: 15px;
  }
  .expanded-detail {
    padding: 16px;
  }
  .reading-finish {
    padding: 24px;
  }
  .back-top span {
    display: none;
  }
  .back-top {
    min-width: 44px;
    text-align: center;
  }
}
@media print {
  .back-top,
  .reading-progress-line {
    display: none !important;
  }
  .reading-chapter + .reading-chapter {
    break-before: page;
    margin-top: 0;
    border: 0;
  }
  .reading-chapter .figure-card button {
    display: block !important;
  }
  .reading-chapter .content-section {
    break-inside: auto;
  }
}